George Santayana - "Mightier storms than this are brewed on earth" lyrics

Mightier storms than this are brewed on earth That pricks the crystal lake with summer showers. The past hath treasure of sublimer hours, And God is witness to their changeless worth. Big is the future with portentous birth Of battles numberless, and nature's powers Outdo my dreams of beauty in the flowers, And top my revels with the demons' mirth. But thou, glad river that hast reached the plain, Scarce wak'st the rushes to a slumberous sigh. The mountains sleep behind thee, and the main Awaits thee, lulling an eternal pain With patience; nor doth Phoebe, throned on high, The mirror of thy placid heart disdain.